233 lines
13 KiB
Markdown
233 lines
13 KiB
Markdown
[alg.search]
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# 26 Algorithms library [[algorithms]](./#algorithms)
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## 26.6 Non-modifying sequence operations [[alg.nonmodifying]](alg.nonmodifying#alg.search)
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### 26.6.15 Search [alg.search]
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[ð](#lib:search)
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`template<class ForwardIterator1, class ForwardIterator2>
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constexpr ForwardIterator1
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search(ForwardIterator1 first1, ForwardIterator1 last1,
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ForwardIterator2 first2, ForwardIterator2 last2);
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template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2>
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ForwardIterator1
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search(ExecutionPolicy&& exec,
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ForwardIterator1 first1, ForwardIterator1 last1,
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ForwardIterator2 first2, ForwardIterator2 last2);
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template<class ForwardIterator1, class ForwardIterator2,
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class BinaryPredicate>
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constexpr ForwardIterator1
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search(ForwardIterator1 first1, ForwardIterator1 last1,
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ForwardIterator2 first2, ForwardIterator2 last2,
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BinaryPredicate pred);
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template<class ExecutionPolicy, class ForwardIterator1, class ForwardIterator2,
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class BinaryPredicate>
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ForwardIterator1
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search(ExecutionPolicy&& exec,
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ForwardIterator1 first1, ForwardIterator1 last1,
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ForwardIterator2 first2, ForwardIterator2 last2,
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BinaryPredicate pred);
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`
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[1](#1)
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[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/algorithms.tex#L5839)
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*Returns*: The first iterator i in the range [first1, last1 - (last2 - first2)]
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such that
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for every non-negative integer n less than last2 - first2 the following corresponding conditions hold:*(i + n) == *(first2 + n), pred(*(i + n), *(first2 + n)) != false[.](#1.sentence-1)
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Returns first1 if [first2, last2) is empty,
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otherwise returns last1 if no such iterator is found[.](#1.sentence-2)
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[2](#2)
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[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/algorithms.tex#L5849)
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*Complexity*: At most (last1 - first1) * (last2 - first2) applications
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of the corresponding predicate[.](#2.sentence-1)
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[ð](#lib:search_)
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`template<[forward_iterator](iterator.concept.forward#concept:forward_iterator "24.3.4.11 Concept forward_iterator [iterator.concept.forward]") I1, [sentinel_for](iterator.concept.sentinel#concept:sentinel_for "24.3.4.7 Concept sentinel_for [iterator.concept.sentinel]")<I1> S1, [forward_iterator](iterator.concept.forward#concept:forward_iterator "24.3.4.11 Concept forward_iterator [iterator.concept.forward]") I2,
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[sentinel_for](iterator.concept.sentinel#concept:sentinel_for "24.3.4.7 Concept sentinel_for [iterator.concept.sentinel]")<I2> S2, class Pred = ranges::equal_to,
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class Proj1 = identity, class Proj2 = identity>
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requires [indirectly_comparable](alg.req.ind.cmp#concept:indirectly_comparable "24.3.7.5 Concept indirectly_comparable [alg.req.ind.cmp]")<I1, I2, Pred, Proj1, Proj2>
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constexpr subrange<I1>
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ranges::search(I1 first1, S1 last1, I2 first2, S2 last2, Pred pred = {},
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Proj1 proj1 = {}, Proj2 proj2 = {});
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template<[forward_range](range.refinements#concept:forward_range "25.4.6 Other range refinements [range.refinements]") R1, [forward_range](range.refinements#concept:forward_range "25.4.6 Other range refinements [range.refinements]") R2, class Pred = ranges::equal_to,
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class Proj1 = identity, class Proj2 = identity>
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requires [indirectly_comparable](alg.req.ind.cmp#concept:indirectly_comparable "24.3.7.5 Concept indirectly_comparable [alg.req.ind.cmp]")<iterator_t<R1>, iterator_t<R2>, Pred, Proj1, Proj2>
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constexpr borrowed_subrange_t<R1>
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ranges::search(R1&& r1, R2&& r2, Pred pred = {},
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Proj1 proj1 = {}, Proj2 proj2 = {});
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template<[execution-policy](algorithms.parallel.defns#concept:execution-policy "26.3.1 Preamble [algorithms.parallel.defns]") Ep, [random_access_iterator](iterator.concept.random.access#concept:random_access_iterator "24.3.4.13 Concept random_access_iterator [iterator.concept.random.access]") I1, [sized_sentinel_for](iterator.concept.sizedsentinel#concept:sized_sentinel_for "24.3.4.8 Concept sized_sentinel_for [iterator.concept.sizedsentinel]")<I1> S1,
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[random_access_iterator](iterator.concept.random.access#concept:random_access_iterator "24.3.4.13 Concept random_access_iterator [iterator.concept.random.access]") I2, [sized_sentinel_for](iterator.concept.sizedsentinel#concept:sized_sentinel_for "24.3.4.8 Concept sized_sentinel_for [iterator.concept.sizedsentinel]")<I2> S2,
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class Pred = ranges::equal_to, class Proj1 = identity, class Proj2 = identity>
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requires [indirectly_comparable](alg.req.ind.cmp#concept:indirectly_comparable "24.3.7.5 Concept indirectly_comparable [alg.req.ind.cmp]")<I1, I2, Pred, Proj1, Proj2>
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subrange<I1>
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ranges::search(Ep&& exec, I1 first1, S1 last1, I2 first2, S2 last2,
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Pred pred = {}, Proj1 proj1 = {}, Proj2 proj2 = {});
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template<[execution-policy](algorithms.parallel.defns#concept:execution-policy "26.3.1 Preamble [algorithms.parallel.defns]") Ep, [sized-random-access-range](range.refinements#concept:sized-random-access-range "25.4.6 Other range refinements [range.refinements]") R1, [sized-random-access-range](range.refinements#concept:sized-random-access-range "25.4.6 Other range refinements [range.refinements]") R2,
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class Pred = ranges::equal_to, class Proj1 = identity, class Proj2 = identity>
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requires [indirectly_comparable](alg.req.ind.cmp#concept:indirectly_comparable "24.3.7.5 Concept indirectly_comparable [alg.req.ind.cmp]")<iterator_t<R1>, iterator_t<R2>, Pred, Proj1, Proj2>
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borrowed_subrange_t<R1>
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ranges::search(Ep&& exec, R1&& r1, R2&& r2,
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Pred pred = {}, Proj1 proj1 = {}, Proj2 proj2 = {});
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`
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[3](#3)
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[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/algorithms.tex#L5887)
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*Returns*:
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- [(3.1)](#3.1)
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{i, i + (last2 - first2)},
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where i is
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the first iterator in the range [first1, last1 - (last2 - first2)]
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such that
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for every non-negative integer n less than last2 - first2 the conditionbool(invoke(pred, invoke(proj1, *(i + n)), invoke(proj2, *(first2 + n)))) is true.
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- [(3.2)](#3.2)
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Returns {last1, last1} if no such iterator exists.
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[4](#4)
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[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/algorithms.tex#L5905)
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*Complexity*: At most (last1 - first1) * (last2 - first2) applications
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of the corresponding predicate and projections[.](#4.sentence-1)
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[ð](#lib:search_n)
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`template<class ForwardIterator, class Size, class T = iterator_traits<ForwardIterator>::value_type>
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constexpr ForwardIterator
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search_n(ForwardIterator first, ForwardIterator last,
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Size count, const T& value);
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template<class ExecutionPolicy, class ForwardIterator, class Size,
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class T = iterator_traits<ForwardIterator>::value_type>
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ForwardIterator
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search_n(ExecutionPolicy&& exec,
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ForwardIterator first, ForwardIterator last,
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Size count, const T& value);
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template<class ForwardIterator, class Size, class T = iterator_traits<ForwardIterator>::value_type,
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class BinaryPredicate>
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constexpr ForwardIterator
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search_n(ForwardIterator first, ForwardIterator last,
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Size count, const T& value,
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BinaryPredicate pred);
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template<class ExecutionPolicy, class ForwardIterator, class Size,
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class T = iterator_traits<ForwardIterator>::value_type,
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class BinaryPredicate>
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ForwardIterator
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search_n(ExecutionPolicy&& exec,
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ForwardIterator first, ForwardIterator last,
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Size count, const T& value,
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BinaryPredicate pred);
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`
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[5](#5)
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[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/algorithms.tex#L5942)
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*Mandates*: The type Size is convertible to an integral type ([[conv.integral]](conv.integral "7.3.9 Integral conversions"), [[class.conv]](class.conv "11.4.8 Conversions"))[.](#5.sentence-1)
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[6](#6)
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[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/algorithms.tex#L5947)
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Let E be pred(*(i + n), value) != false for the overloads with a parameter pred,
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and *(i + n) == value otherwise[.](#6.sentence-1)
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[7](#7)
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[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/algorithms.tex#L5952)
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*Returns*: The first iterator i in the range [first, last - count]
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such that for every non-negative integer n less than count the condition E is true[.](#7.sentence-1)
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Returns last if no such iterator is found[.](#7.sentence-2)
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[8](#8)
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[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/algorithms.tex#L5959)
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*Complexity*: At most last - first applications of the corresponding predicate[.](#8.sentence-1)
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[ð](#lib:search_n_)
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`template<[forward_iterator](iterator.concept.forward#concept:forward_iterator "24.3.4.11 Concept forward_iterator [iterator.concept.forward]") I, [sentinel_for](iterator.concept.sentinel#concept:sentinel_for "24.3.4.7 Concept sentinel_for [iterator.concept.sentinel]")<I> S,
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class Pred = ranges::equal_to, class Proj = identity,
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class T = projected_value_t<I, Proj>>
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requires [indirectly_comparable](alg.req.ind.cmp#concept:indirectly_comparable "24.3.7.5 Concept indirectly_comparable [alg.req.ind.cmp]")<I, const T*, Pred, Proj>
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constexpr subrange<I>
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ranges::search_n(I first, S last, iter_difference_t<I> count,
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const T& value, Pred pred = {}, Proj proj = {});
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template<[forward_range](range.refinements#concept:forward_range "25.4.6 Other range refinements [range.refinements]") R, class Pred = ranges::equal_to,
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class Proj = identity, class T = projected_value_t<iterator_t<R>, Proj>>
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requires [indirectly_comparable](alg.req.ind.cmp#concept:indirectly_comparable "24.3.7.5 Concept indirectly_comparable [alg.req.ind.cmp]")<iterator_t<R>, const T*, Pred, Proj>
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constexpr borrowed_subrange_t<R>
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ranges::search_n(R&& r, range_difference_t<R> count,
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const T& value, Pred pred = {}, Proj proj = {});
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template<[execution-policy](algorithms.parallel.defns#concept:execution-policy "26.3.1 Preamble [algorithms.parallel.defns]") Ep, [random_access_iterator](iterator.concept.random.access#concept:random_access_iterator "24.3.4.13 Concept random_access_iterator [iterator.concept.random.access]") I, [sized_sentinel_for](iterator.concept.sizedsentinel#concept:sized_sentinel_for "24.3.4.8 Concept sized_sentinel_for [iterator.concept.sizedsentinel]")<I> S,
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class Pred = ranges::equal_to, class Proj = identity,
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class T = projected_value_t<I, Proj>>
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requires [indirectly_comparable](alg.req.ind.cmp#concept:indirectly_comparable "24.3.7.5 Concept indirectly_comparable [alg.req.ind.cmp]")<I, const T*, Pred, Proj>
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subrange<I>
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ranges::search_n(Ep&& exec, I first, S last, iter_difference_t<I> count,
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const T& value, Pred pred = {}, Proj proj = {});
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template<[execution-policy](algorithms.parallel.defns#concept:execution-policy "26.3.1 Preamble [algorithms.parallel.defns]") Ep, [sized-random-access-range](range.refinements#concept:sized-random-access-range "25.4.6 Other range refinements [range.refinements]") R, class Pred = ranges::equal_to,
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class Proj = identity, class T = projected_value_t<iterator_t<R>, Proj>>
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requires [indirectly_comparable](alg.req.ind.cmp#concept:indirectly_comparable "24.3.7.5 Concept indirectly_comparable [alg.req.ind.cmp]")<iterator_t<R>, const T*, Pred, Proj>
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borrowed_subrange_t<R>
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ranges::search_n(Ep&& exec, R&& r, range_difference_t<R> count,
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const T& value, Pred pred = {}, Proj proj = {});
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`
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[9](#9)
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[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/algorithms.tex#L5996)
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*Returns*: {i, i + count} where i is the first iterator in the range [first, last - count]
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such that for every non-negative integer n less than count,
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the following condition holds:invoke(pred, invoke(proj, *(i + n)), value)[.](#9.sentence-1)
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Returns {last, last} if no such iterator is found[.](#9.sentence-2)
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[10](#10)
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[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/algorithms.tex#L6005)
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*Complexity*: At most last - first applications
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of the corresponding predicate and projection[.](#10.sentence-1)
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[ð](#lib:search__)
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`template<class ForwardIterator, class Searcher>
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constexpr ForwardIterator
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search(ForwardIterator first, ForwardIterator last, const Searcher& searcher);
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`
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[11](#11)
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[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/algorithms.tex#L6019)
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*Effects*: Equivalent to: return searcher(first, last).first;
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[12](#12)
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[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/algorithms.tex#L6023)
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*Remarks*: Searcher need not meet the [*Cpp17CopyConstructible*](utility.arg.requirements#:Cpp17CopyConstructible "16.4.4.2 Template argument requirements [utility.arg.requirements]") requirements[.](#12.sentence-1)
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